The National Retail Federation, which lobbies on behalf of companies such as Macy&rsquo;s and Kohl&rsquo;s, today predicted solid growth for the upcoming holiday season. But the trade group warned lawmakers that the &ldquo;fiscal cliff&rdquo; of looming tax increases and spending cuts could hurt consumer spending at a critical time for the industry.

&ldquo;Congress&rsquo; inability to act on the key measures that would ease consumers&rsquo; fears ... really could be best described as the Grinch that stole Christmas,&rdquo; NRF&rsquo;s president Matt Shay said during a conference call with reporters. The political wrangling over the fiscal cliff, he added, &ldquo;could jeopardize how this holiday season plays out.&rdquo;

The retail association forecasts holiday sales this year will increase 4.1 percent, to $586.1 billion, which Shay called the group&rsquo;s most optimistic prediction since the recession. It&rsquo;s still below last year&rsquo;s actual holiday sales of 5.6 percent growth, he added.

The sector also is likely to add about 600,000 jobs for the season, he said. &ldquo;Santa&rsquo;s helpers are going to be on the hook for some overtime this year,&rdquo; he said.

But he noted that consumer anxiety over the economy remains with fiscal and political uncertainties, high unemployment and minimal income growth.

Gridlock in Washington, D.C., he said, has a chilling effect for consumers.

NRF&rsquo;s chief economist, Jack Kleinhenz, said the political uncertainty and jitters are real, according to data compiled for the group by market research firm BIGinsight. &ldquo;They do influence spending,&rdquo; he said. But he noted that other factors such as the weather will play a role in retailers&rsquo; success.

Shay said the group may reassess its holiday predictions and added that forecasting the holiday season &ldquo;is like tracking a hurricane.&rdquo;

One sure bet, though, is that consumers will do more shopping online using tablet computers and smartphones. One of NRF&rsquo;s policy priorities is legislation that would compel states to collect sales tax from online retailers.

&ldquo;Online retail has been a bright spot for years, and we don&rsquo;t expect that trend to change anytime soon, especially with the growth in mobile,&rdquo; Shay said.